GCE Chemistry 2020
Past Questions

The bond angle in a molecule of BF₃ is

The lattice energy of an ionic compound can be calculated using a Born-Haber cycle. Given the following data for the formation of sodium chloride: enthalpy of formation = $-411$ kJ/mol, atomization en…

How many moles of atoms are contained in 4.0 g of calcium? [Ca = 40]

Graham's Law of diffusion states that the rate of diffusion of a gas is inversely proportional to the square root of its molar mass. If gas X diffuses twice as fast as gas Y, what is the ratio of the …

For the reaction: $N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)$, $\Delta H = -92\,kJ\,mol^{-1}$. Which condition would shift the equilibrium to the right to produce more ammonia?

The equilibrium constant expression for the reaction $2SO_2(g) + O_2(g) \rightleftharpoons 2SO_3(g)$ is

Consider the equilibrium: $CaCO_3(s) \rightleftharpoons CaO(s) + CO_2(g)$. The correct expression for the equilibrium constant $K_c$ is

What volume of oxygen (measured at s.t.p.) is required for the complete combustion of 2.0 dm³ of propane gas at s.t.p.? [C₃H₈ + 5O₂ → 3CO₂ + 4H₂O]

A compound X has the empirical formula CH₂O and a molar mass of 180 g mol⁻¹. The molecular formula of X is

In an experiment, 5.6 g of iron filings were added to excess dilute tetraoxosulphate(VI) acid. The reaction proceeded according to the equation: Fe(s) + H2SO4(aq) → FeSO4(aq) + H2(g) [Fe = 56, S = 32,…

a) Define the following terms as applied to acids and bases: i) Arrhenius acid ii) Brønsted-Lowry base iii) Lewis acid b) A 25.0 cm³ sample of hydrochloric acid required 20.0 cm³ of 0.150 mo…